SB 



A Talk on Weeds 





Class j.S^-^^^" 
Book— ^-^^^-S- 

GopyrightN^ 

COPYRIGHT DEPOSrr 



A Talk on Weeds 



An address delivered before the County 
Road School, Clinton County, Iowa, 1910, 
with an appendix describing a few weeds 




BY 

L. H. PAMMEL, PH. D. 

PROFESSOR OF BOTANY, IOWA STATE COLLEGE 
AMES. IOWA 



6^!^^^^ 



Copyright 1910 by 
L. H. Pammel 



>v 



1 



)C!.A27:r/20 



Table of Contents 



PAGE 

What is a Weed, Kinds of Weeds, Annual, Winter Annual 5 

Biennial, Perennial, How Weeds Spread, Vegetative Propagration. . . 6 

Seed Propagation, Dissemination or Scattering of Plants 7 

Water, Animals 8 

Explosive Properties, Seeds Burying Themselves 9 

Man as an Agent, Impure Seeds 10 

Iowa Pure Seed Law 11 

Threshing Machines, Cultivation, Packing Material, Plants, Culti- 
vated for Ornamental Purposes, Iowa Weed Law. 16 

Other Weeds, Treatment of Weeds 20 

Perennial Weeds 21 

Quack Grass, The Cover Method, Canada Thistle and Horse Nettle. . .22 

Morning Glory and Milk Weed 23 

Indian Mallow 24 

Sweet Clover, Greater Ragweed or Kinghead, Cocklebur 25 

Weeds of Special Crops, Small Grain, Corn 26 

Garden Weeds, Meadows, Pastures, Roadsides, Poisonous Weeds 27 

Grass Family, Yellow Foxtail 30 

Green Foxtail, Quack Grass ' 31 

Drop Seed Grass, Squirreltail Grass 33 

Crab Grass, Sedge Family, Dock and Smartweed 34 

Curled Dock .35 

Pale Dock, Sheep Sorrel 36 

Goosefoot Family, Pigweed Family, Pink Family 37 

Purslane Family 38 

Crowfoot Family, Mustard Family 40 

Mallow Family 41 

Velvet Weed, Parsley Family 42 

Parsnip, Carrot 43 

Oowbane 44 

Morning Glory, Dodder 45 

Mint Family 47 

Nightshade. Horse Nettle 48 

Plantain, Buckhorn, Composite, Bull Thistle 49 

Canada Thistle, Cockle Bur, Ragweed 50 

Burdock 51 

Suggestions for the Teacher 52 

Questions and Topics 53 

Bibliography 55 



A STUDY OF WEEDS IMPORTANT 



I am invited to address you this afternoon on the subject of 
weeds. I am sure you will agree with me that this is a most 
important sul),ject I'or the farmers of Iowa and those wlio are in- 
terested in makiuy our state beautiful. The weeds in villages, 
cities, along the highways and on our farms are a continual men- 
ace to the agriculture of this state. It is important that we be- 
gin to realize the menace that weeds are to our agriculture. Iowa 
should realize the importance of this problem and we should be- 
gin at once to clean up, because it is far more economical to do 
so now than in a decade. 

WHAT IS A WEED. 

A weed has been defined as a plant out of place. This defini- 
tion is concise, but is as good as any. Oats growing in a wheat 
field, if not wanted there, must be looked upon as a weed. A 
weed may also be defined as a plant detrimental to the growth 
of a garden or farm crop, in short detrimental to horticulture 
and agriculture. A great many people regard plants which have 
inconspicnous fiowers as weeds; they exclude, of course, such 
plants as are cultivated for some purpose. S^ich people regard 
the inconspicuous plants of the forest as weeds, forgetting that 
plants like the Dutchman's Breeches, Bloodroot and Hepatica 
are most useful plants in the forest and are just as much a 
part of it as the oak or maple. They do not, however, regard 
bhv /rass as a Aveed. In the forest, however, bluegrass must be 
rey /rded as a weed. In a bluegrass pasture such plants as fox- 
tai/, golden rod, vervain and crabgrass are weeds. They check 
the growth of this useful forage plant. 

KIND OF WEEDS. 

AVeeds may be classified according to their duration of life 
into the following classes; annual, wdnter annual, biennial and 
perennial. 

AnnnaJ. — The annual Aveeds are the most numerous and are 
easily recognized. The seed germinates in the spring, it sends 
up a stem which produces flowers and seeds the same season and 
then dies. Foxtail, ragweed or kinghead, smartweed, crabgrass, 
horseweed belong to this class. A large number of our weeds 
belong to this class. 

Winter Annual. — These weeds do not differ essentially from 



the annual. The seed germinates in the fall, a mat of leaves is 
produced and the next spring a stalk is sent up which produces 
flowers and seed, then dies. Shepherd's purse, wild harley or 
squirrel tail, pepper grass in our climate, but in the south 
many more weeds belong to this class. Winter wheat and win- 
ter rye are winter annuals. 

Biennial. — The seeds of biennial weeds germinate in the spring, 
the plant produces a mat of leaves with a short stem, it passes 
through the winter in this way, the next season it sends up a 
stem on which flowers and seed are produced. This ends its 
existence. Burdock, Parsnip, Carrot, Mullein, and Bull Thistle 
are representatives of this type. These weeds are common every- 
where in the s't.ate. 

Perennial. — Thv perennial weeds are often long lived. The 
seed germinates, somtl'mes a stalk with flowers is produced the 
same season. The '"lant continues to live year after year. Peren- 
nial weeds are th«- most difficult to exterminate. Weeds of this 
type are numerous and in Iowa are represented by Canada 
thistle, Morning glory, IMilkweed, Quack grass. Nimble will. 

HOW WEEDS SPREAD. 

Weeds spread in two days by (1) vegetative propagation and 
(2) seed production. Some weeds have both methods, some 
only one. 

Vegetative Propagation. — In this method of reproduction the 
stem or root serves to propagate the plant. This is brought 
about in three ways, (a) by stem above ground or under- 




Tumbleweed (,Aniaranthns graecizans). Scattered by the wind against a 
fence. (Bergen.) 



ground. The stem may be recognized through the presence of 
leaves or scales. Quack grass, Germander, Northern nut grass, 
and IVIorning glory spread by stems. The Quack grass stems, 
called roots commonly are near the surface of the soil, some- 
times over three feet long, and every severed part gives rise 
to a new plant, (b) These plants spread by roots, sometimes 
they are Sehsy and in other cases they are thin and slender. 
Dock, Horseradish, Horse nettle, Sheep sorrel and Dandelion. The 
Milkweed spreads horizontally in the soil and may attain a length 
of 14 feet. The roots of the Horse nettle on the other hand 
spread deeply in the soil, sometimes to a depth of three and one- 
half feet. These roots, when severed give rise to new plants, 
buds forming on these roots, (c) The third type propagates 
partly by root and partly by stem. The upper part of the 
Canada thistle is stem, bearing minute scales (leaves), the lower 

root which develops buds. 

iieed Fropagation. — The vast majority of weeds produce seeds. 
The only weed in the state which has never been known to pro- 
duce seed is the Horse Radish. It flowers frequently but seeds 
are never produced. The Canada thistle blossoms freely but it 
does not seed abundantly. At least this is true for Iowa. It 
relies chiefly, therefore, on vegetative reproduction. The quack 
grass spreads as freely by seeds as by its underground stems. 
Some weeds produce an enormous number of seeds, from a 
few thouand to over a hundred thousand on a single plant. A 
single seed of Squirrel tail grass germinates, from this seed a 
large number of stems arise, each with a spike that contains 50 
or 60 seeds, so that the progeny soon becomes greatly multi- 
plied. 

Dr. Beal estimates that a large purslane plant produces 1,250,- 
000 seeds, a patch of daisy fleabane 3,000 to the square inch. 
We found the following number of seeds per plant, horseweed 
324,000; pigweed, 115,G00; Jimson weed, 89,100. Dr. Halsted 
found seeds in some weeds as follows: Speedwell, 186,292; 
Shepherd's purse, 17,600; Pepper grass, 12,225; Charlock, 9,900. 
Hitchcock and Clothier record the weeds seeds as follows: Yellow 
foxtail, 113,600; stink grass, 180,000; cocklebur, 9,700. 

DISSEMINATION OR SCATTERING OP PLANTS. 

The scattering of plants is called dissemination and this is 
accomplished in the following ways: (a) wind; (b) water; (c) 
animals; (d) explosive properties; (e) seeds burying them- 
selves; (f) man as an agent. 

Wind. — The wind is an important agent in a large number 
of weeds. The dandelion may serve as an illustration. The 
"seed" is cylindrical with a long beak, coming from the beak 



are a large number of fine threads, collectively called the pap- 
pus. These give it a parachute-like arrangement and permit the 
seed to sail through the air. This weed owes its wide distribu- 
tion to the facilities for dissemination. Canada thistle, Bull 
thistle, Horseweed and many plants of the Sunflower family have 
similar contrivances. The Tumhleweed is another type of weed 





a — -Seed of beggar-tick's, b — Spanish needle carried by animals. (C. M. 
King.) 

Seeds carried by the wind: « — golden rod, b — blue lettuce. (C. M. King.) 

di.sseminated by the wind. The plant grows in circular form and 
when mature is severed from the root close to the ground. In 
this form it rolls over and over scattering the seed. The Rus- 
sian thistle is like it, but each seed is attached by a slender thread 
like body which becomes severed from the plant, drops the seed 
as it rolls over the ground. 

Water. — Weeds are scattered by the water in two ways (a) 
in a mechanical way, the seeds, plants or roots are carried by 
the water. I have seen fields covered with wild oats that had 
come from higher ground along the streams or ridges, stems of 
Quack grass have been scattered by the water in this way. (b) 
Many seeds have bladders filled with air, as in Dock. The 
three cornered seed is surrounded by the calyx; one or more of 
the lobes contain a cylindrical body called the tubercle, this is 
filled with air and makes the seed boyant which enables it to 
float down the stream and scatter the seed wherever it is lodged. 
The seeds of Peppergrass when moistened become mucilaginous 
and cling to the hoofs of animals or shoes and in this way steal 
a ride. 

Animals. — Various animals like cattle, sheep, horses, squirrels. 



8; 

birds, etc., scatter seeds and fruits. This is done in two ways: 
(a) Where the fruit or seed is edible as in the black night shade, 
cherry, poison ivy, seed of dandelion, thistle, etc., crows scatter 
large numbers of seeds of the poison ivy. Millions of these 
poison ivy seeds are annually consumed by birds. Large num- 
bers of seeds of the dandelion, thistle, foxtail are consumed by 
birds some of these are accidentally scattered in this way. Birds 
are undoubtedly useful, however, in destroying large numbers 
of weed seed. The colored fruits usually have hard seeds so 
that they can pass the digestive tract of birds uninjured, (b) 
In the second type the seeds cling to animals. Many of our 
weeds have excellent contrivances for such dissemination. We 
will mention in this connection the cocklebur. Each cocklebur 
has two so-called seeds. The bur is provided with hooks tnae 
cling to any passing animal and I have seen them scattered for 
miles. The Burdock, another pltint of the same family, has num- 
erous seeds in a head ; the hooked appendages get in the hair, 
tails of horses, cattle, etc., where they form balls and thus the 
seed is scattered. The Spanish needle or boot jack of the same 
family has a flattened seed with two slender pointed bodies that 
are barbed downwardly like grappling irons ; these cling to pass- 
ing animals and carry the seed. Another weed, the Tick Trefoil, 
belonging to the Pea family has a pod containing several seeds, 
this pod breaks up into separate pieces when ripe, each contain- 
ing a sin.'ile seed. The pod is provided with hairs that are hooked 
and so clings to animals. When removed the seed has often trav- 
eled a long distance with the animal. ]\fany other seeds of this 
family like Licorice may be mentioned. Weeds with similar 
contrivances are found in members of the Borage family, like 
Hound's tongue, stickseed, etc. 

Explosive Properties. — The seeds of a few weeds have explo- 
sive properties. The seeds of the common yellow field sorrel has 
a straight pod which, when mature and touched, shoots out the 
seed like shot from a gun. The pods of certain vetches contract 
and twist when mature, forcing the seed out. Contraction of 
capsule of the three-seeded mercury scatters the seed, throwing 
it some distance. This method of scattering can be observed bet- 
ter on such a plant as the common Castor oil bean. 

Seeds Burying Themselves. — A few of our weeds bury their 
seed, but the needle grass growing on our dry sterile hills has 
a sharp point to its "fruit," with small hairs which point obli- 
quely upward. There is also a long awn to the fruit, this is sen- 
sitive to moisture, it contracts when dry and straightens out 
V hen moist and in this way buries the seed. 



MAN AS AN AGENT. 

Man is an agent in many different waj^s of which the follow- 
ing may serve as illnstrations : (a) impure seeds; (b) railways; 
(c) vehicles; (d) threshing machines ; (e) cultivation; (f) pack- 
ing materials; (g) wool; (h) plants cultivated for ornamental 
purposes; (i) cultivated for food. 

Impure Seeds. — Many weed seeds are scattered with various 
agricultural and garden seeds. Buekhorn, dodder, wild carrot, 
ragweed, nimble will, braeted plantain, dock, quack grass, chic- 
ory, Canada thistle and many other weeds have been scattered 




Some of the impurities found in alfalfa : la — alfalfa seed, Ih — toothed 
bur-clover, Ic — spotted bur-clover, 2c — yellow trefoil, 2b — seed natural size. 
2d — pod, Sa — .sweet clover, ib — seed natural size, tc — braeted plantain (Plati- 
tago aristata), 5— buekhorn (Plantago lance olata) , 6 — sour dock, 7 — Canada 
thistle, 8 — dodder, 9 — quack grass, 10 — sheep sorrel, 11 — -wire prass or Canada 
bluegrass {Poa comprcssa) , 12 — bluegrass. (Lettered figures after Hillman.) 

with Agricultural seed.s. One farmer in Iowa sent to me twenty 
ditferent kinds of weeds found in his clover meadow which were 



10. 

introduced with clover seed. In some cases it is diflrtcnlt to 
separate the weed seeds from clover seed as dock, buckhorn and 
bracted plantain. In other cases there is no excuse for the pres- 
ence of those weed seeds. One can nearly always tell where the 
seed comes from because of the presence of certain weed seeds. 

It may be of interest to give a few statistics on the weed seeds 
commonly found in some of our agricultural seeds. 

Iowa Standard 
K ind of Seed Purity Vitality Purity Vitalit y 

Alfalfa 91.1 ' 87.6 ' 96. 80.' 

Red Clover 96.6 87.8 92. 80. 

Alsike Clover 98.6 87. 

White Clover 98.9 76.6 90. 75. 

Timothy 98.9 84.1 ■ 96. 85. 

Millet .' 96. 60 90 8ix_ 

The more important impurities found in red clover vary with 
the season. The imported seed may contain Canada thistle, 
dodder, buckhorn, evening catchfly, wild carrot. Iowa grown 
clover seed usually contains none of the above, but ragweed, dock, 
smartweed, plantain, dropseed grass, foxtail and sheep sorrel are 
eonunon. Western grown alfalfa may contain black medick, burr 
clover, chicory. The seed of sheep sorrel, yellow foxtail and 
curled dock may also occur. Bachellor's button seed as well as 
that of evening catchfly indicates European grown seed. Tim- 
othy seed generally contains peppergrass, curled dock, common 
plaintain. The seed of oats may contain quackgrass and mus- 
tard. Wheat seed contains the seed of vetch, corncockle, chess, 
cowherb and mustard. 

IOWA PURE SEED LAW. 

Seed Legislation. — The Iowa law has the following provisions 
in regard to the sale of seed: 

Sec. 9. The term, agricultural seeds, as used in this act, shall 
include the seeds of the red clover, white clover, alsike clover, 
alfalfa, Kentucky blue grass, timothy, brome grass, orchard 
grass, red top, meadow fescue, oat gi'ass, rye grass and other 
grasses and forage plants, flax, rape and cereals. 

Section. 10. No person shall sell, offer, or expose for sale or 
distribution, in this state, for the purpose of seeding, any of 
the agricultural seeds as defined in Section Nine (9 of this act, 
unless the said seeds are free from the seeds of the following 
weeds: Wild mustard or charlock (Brassica sinapistrum), quack 
grass (Agropyrou repens), Canada thistle (Cnicus arvensis), 
wild oats (Avena fatua), clover and alfalfa dodder (Cuscuta 



n. 

epithymura), field dodder (Cuscuta arvensis), and corn cockle 
Lychnis githago). * 

Sec. 11. The seeds of the following weeds shall be considered 
as impurities in the agricultural seeds, as defined in Section Nine 
(9) of this act, sold, ofilered, or exposed for sale, within the 
state for the purpose of seeding: White cockle (Lychnis ves 
pertina), night flowering catchfly (Silene noctiflora), curled dock 
(Rumex crispus), smooth dock (Rumex altissimus), sheep sor- 




Impurities found in red clover: 1 — bull thistle, 2 — Canada thistle, 3 — 
green foxtail (Setai-ia viridis), 4 — common plantain (Plantago Rugelii), 5 — 
pepper grass (also found in timothy), 6 — chicory, 7 — pigeon grass (Setaria 
glauca), 8 — crabgrass {Panicum sanguinale), 9 — old witch grass, 10 — timothy, 
11 — wild carrot, 12 — pigweed {Amuranthus retroffexus) , 13 — smartweed (Poly- 
gonum Persicaria), 14 — lamb's quarter, 15 — dropseed grass {Muhlenhergia) . 
(Charlotte M. King.) 

*The scientific names have been changed since this law was enacted. 
The botanical names now recognized are as follows: — Common Mustard 
or Charlock (brassica arven.sis) Canada Thistle (cirsium arvense) 
Corn Cockle (agrostemma githago) The weed law has the names 
now generally recognized. 



12. 

rel (Rumex acetosella), yellow trefoil (Medieago lupulina), bun- 
clover (IMedicaiio deiiticiilata), sweet clover (jMelilotns alba and 
oriieinalis) black inustnrd (Brassica nigra), plantain, buekhorn 
(Plantago laneeolata), bracted plantain (Plantago aristata), 
bindweed (Convolvulus sepiuni), smooth crab grass (Panicum 
glabrum), common chick weed (Stellaria media). When such 
ijn])vuities or any of them are present in quantity exceeding a 
total of two per cent of the weight of said agricultural seeds, the 
approximate percentage of each shall be plainly indicated in 
statement specified in Section One (1) of this act. 

It will be seen from the above extracts that seed cannot be 
sold that contains more than two per cent (2'^'J ) of the weeds 
specified in Section Eleven. An amendment was made to Sec- 
tion Ten stating that the weeds specified tli«rein must not be 
present in quantities of more than one in ten thousand, and 
that due diligence has been used to find and remove said seeds. 

The Iowa law has greatly improved the (juality of seed sold in 
the state. The farmers are demanding a better quality of seed. 
The seed merchants will supply the demand but the seeds can- 
not to be sold for the same price. In cleaning there is consider- 
able loss and the farmer should be willing to pay for this. It 
will cost more to remove the bad weeds than the additional 
price paid for the better seed. 

SOME WEED SEKDS 

Characters of a Few Meed Seeds. — The seeds of Canada thistle 
are about 1-8 of an inch long, lance shaped in oatline, tapering 
towards the base, the upper part is cup .shaped, with a yellowish 
rim, a conspicuous point appeai-ing in the center. The Bull 
thistle is much like it, but larger. The seeds of dodder vary 
from 1-16 to 1-24 of an inch in diameter, somewhat flattened 
and egg-shaped ; the color varies fi'om yellowish to light or dark 
green, rough and dull, not smooth as in clover and alfalfa. 
There are two forrns of dodder, the field dodder with large seeds 
and the clover dodder. The seeds of quack grass are sometimes 
difficult to distinguish from some related species and should be 
submitted to a botanist. Bull. 115 of the Iowa Agricultural Ex- 
periment Station describes them. 

The seeds of Ilihgrass or Buekhorn are about 1-10 of an inch 
long, shiny, smooth, dark brown, the back is convex, the rounded 
edges folded inwardly forming a rim. The long longitudinal 
groove of the inner face with a dark colored spot in middle. The 
Bracled plantain is a smaller seed bi-oader and light brown in 
color, a long gi'oove in the center, on the back is a circle. Two 
light colored eirculai" areas in groove are characteristic. The 
seed of the Common pla)itain is black, roughened, flattened with 



13. 

acute edges; they are rhomboidal in outline, from 1-12 to 1-16 
of an inch in Icniitli. The seeds of the Common pigiceed are egg- 
shaped or lens shaped when viewed from the rim or border ; they 
are about 1-24 of an inch in length, smooth and shiny. The 
seed of Goosefoot or Lamb's quarter occur in several forms, us- 
ually nearly spherical with attached parts of the flower, the 
calyx showing ribs. They are dull brown in color. Others with 
a thin membranceous covering. The "seed" is about 1-20 of an 
inch in diameter, nearly spherical, edges somewhat rounded, sur- 
I'acn snnif^v'hat uneven, jot black in color, sometimes brightly 
polished. The "s;'eds" of Chicory are characteristic about 1-10 
ol" an inch in length, marked by longitudinal lines and cross 
lilies. The apex \\ith a double row of whitish scales, color dull, 




Fig. 5 — Mixture of weed seeds commonly found in low-grade alsike clover 
peed : a, alsike clover ; b, white clover ; c, red clover ; d, yellow trefoil ; e, 
Canada thistle; f, dock; g, sorrel; h, buckhorn ; i, rat tail plantain; k, lamb's- 
quarters ; I. sheplierd's-pursc ; tn. mayweed; n, scentless camomile; n, white 
campion ; p, night-flowering catch-fly ; q, oxeye daisy ; r, small-fruited false 
flax ; s, cinquefoil ; t, two kinds of peppergrass ; u, catnip ; v, timothy ; x, 
chickweed ; j/. Canada bluegrass ; z, clover-dodder ; 1, mouse ear ; 2, knot- 
grass ; 8, tumbling amaranth ; '/, rough amaranth ; 3, heal-all ; G, lady's thumb ;. 
(Enlarged.) (Hillman. U. S. Dept. Agr.) 

very dark, brown to straw color. The seeds of Bachellor's hut- 
ton are oblong or ol)ovoid, compressed or 4-angled, smooth and 
shining attached obliquely with a disk on top and an elevated 
margin. These f;eeds occur in alfalfa. 

The seed of May iveed sometimes found in clover is about 1-16 
of an inch in length, bristly club-shaped, the base wider than 
apex, prominently ribbed and tubercled. The "seed" of Small 
Eagwecd is 1-16 — 1-12 of an inch in length, top shaped with 
prominent projecting teeth, sometimes absent, and a beak. Color 
dull. Often the outer part missing and then the dark smooth 



u. 

seed only shows. The greater ragweed is like it but much lar- 
ger. The seeds of Evening catchfly are kidney shaped about 
1-18 of an inch in length, thickish and roughened, dull grayish 
brown. This seed is very common in European and Eastern 
grown clover seed. Several related forms have seed like it. The 
Coiv herb seed, however, is larger and more nearly spherical about 
1-12 of an inch in diameter. Mature seeds jet black, imature 
reddish, the surface is slightly roughened with minute project- 
ing points. Another related seed is Corn cockle; these are about 
1-10 of an inch in diameter, somewhat triangular in outline, 
very rough; color, dull jet black. These seeds commonly occur 
in wheat screenings. It is more or less poisonous. A number of 
seeds in the mustard family are common among them; Field 
mustard, Black mustard, the seeds of these are spherical about 
1-18 of an inch in diameter, blackish, surface covered with a net 
work of delicate ridges. The seeds have a sharp taste. The seeds 
of Pcn)iy cress are somewhat egg shaped, broad in the middle, 
brown, the surface has characteristic, 12-14 curved ridges, color 
of seed reddish brown. The seeds of pepper grass of the same 
family are small, about 1-16 of an inch in length, light reddish 
yellow to brown, elongated, egg shaped, much flattened, the sur- 
face is finely grooved, becomes mucilaginous when moistened. 
The seeds are found in clover and in Iowa especially in timothy. 
The "seeds" of Carrot are flattened, thin, about 1-8 of an inch 
in length, bearing numerous spines, these are generally broken 
off. Color of "seed' is whitish or yellowish. The seeds of S^acA; 
medick are similar to alfalfa, but more egg shaped than kidney 
shaped, they are reddish or greenish with a smooth dull surface. 
The pods are characteristic oval or kidney shaped, spirally coiled 
and blackish. 

The White sweet clover seed is about 1-12 of an inch long, 
somewhat flattened, resembling red clover in outline, elliptical- 
oblong in outline, surface smooth and dull yellowish or green- 
ish. The pods often occur in commercial seed, oval in outline 
1-8 of an inch long, marked with prominent veins, and beaked. 
The seeds of Common vetch are spherical blackish and large. 
The seeds of Cinqucfoil are about 1-24 of an inch in length, straw 
colored with characteristic longitudinal ridges. 

Railways. — The railways scatter many different kinds of weeds. 
The right of Avay of the railway is usually one of the best col- 
lecting grounds for the botanist. Such weeds as sunflower, Buf- 
falo bur, Russian thistle, gum weed, spurge, western wheat grass 
are common along the trunk lines. The seeds drop from passing 
trains. 

Vehicles. — It has often been observed that vehicles of various 



15. 

kinds may be a means of scattering weed seeds. Small weed 
seeds may cling to mud of wheels and be carried to some distance 
away from where the seed was produced. 

Threshing Machines. — Many farmers in northern Iowa where 
quack grass is becoming abundant claim that the seed of this 
weed, mustard, vetch, etc., is scattered by means of the threshing 
machine. I have in some instances verified this claim. 

Cultivation. — The "roots" of various weeds are easily scat- 
tered by the cultivator. A small patch of quack grass in the 
corn field may be the means of widely scattering the plant over 
the field. 

Packing material. — Various kinds of packing material such as 
is used for packing crockery has been the source of the intro- 
duction of Canada tliiptlp, A^vned Brome grass, etc. I have traced 
the origin of these weeds in this way. 

Wool. — The seeds of many weeds cling to the fleece of sheep 
and where the wool is cleaned, and the debris thrown away these 
weeds spring up. Common teasel v>'hich is used to card wool is 
usually found around the woolen mill. Burdock, cocklebur, sand 
bur, and hound's tongue are commonly scattered in this way. 

PLANTS CULTIVATED FOR ORNAMENTAL PURPOSES. 

In this state we have two conspicuous examples of weeds which 
at one time were commonly cultivated for ornamental purposes 
which have become troublesome weeds, namely, the toad flax and 
bouncing betty. Here and there the European bindweed has 
been scattered in this way. These have become troublesome weeds, 
difficult to exterminate because of their perennial character. Live 
forever, cypress spurge, purple pigM'eed and Mexican firweed are 
other illustrations of weeds introduced in this way. 

Plants Cultivated for Food. — We have only a few weeds that 
belong to this class in Iowa, but in some parts of the United 
States they are more numerous. The conspicuous examples are 
chicory, wild carrot, vegetable oyster plant, hemp and parsnip. 

THE WEEDS OP THE IOWA WEED LAW. 

The Thirty-third General Assembly passed a law making it 
the duty to remove certain weeds from the public highway, 
lands adjacent thereto, streets of cities and villages, right of 
way of railroads and public lands. 

Destruction of "Weeds. 
Thirty-third General Assembly of the State of Iowa. 

Section 1. Land Owners or Tenants to Destroy Weeds — 
When. It shall be the duty of every person, firm or corpora- 
tion owning, occupying or controlling lands, town and city lots, 
land used as right of way, depot grounds or for other purposes 
to cut, burn or otherwise entirely destroy all weeds of the kinds 



16^ 

mentioned in section two (2) hereof at such times in each year 
and in such manner as shall prevent the said weeds from bloom- 
ing or coming to maturity. 

Section 2. Noxious Weeds. The following weeds are here- 
by declared to be noxious weeds, namely, quack grass (Agropyron 
repeus), Canada thistle (Cirsium arvense), cocklebur (Xanthium 
Canadense), wild mustard (Brassica arvensis), sour or curled 
dock (Rumex crispus), smooth dock (Rumex altissimus), buck- 
horn or ribbed plaintain (Plantago lanceolata), wild par- 
snip (Pastinaca sativa), horse nettle (Solanum Carolinense), and 
velvet weed or button weed (Abutilon theophrasti) and burdock 
(Arctium lappa). 

Section 3. Destruction on Highways — neglect or Refusal to 
Destroy. It shall be the duty of the township trustees or other 
officers responsible for the care of i)ublic highways in each town- 
ship or county in this state to destroy or cause to be destroyed 
all noxious weeds mentioned in section two (2) hereof or un- 
necessary brush on the highways in such a manner as to effec- 
tually prevent the production of their seeds or their prop;'era- 
tion in any other manner, to warn out labor or to employ laboi- 
for this purpose in the same manner as for repairs to the high- 
ways, and for neglect or failure to perform this work they shall 
be subjected to the penalties in this act. If any occupant of 
lands adjacent to the public highways neglect or refuse to de- 
stroy the noxious weeds upon his land, or shall fail to prevent 
the said noxious weeds from blooming or coming to maturity, 
when such weeds are likely to be the means of infesting the pub- 
lic highway, or upon complaint of any land owner to the town- 
ship trustees that his lands have been or are likely to be infested 
by weeds from the lands of another including railway right of 
Avay, the trustees shall make investigation of such condition or 
complaint and if the same appears to be well founded they shall 
make an order fixing the time within w^hich the weeds shall be 
prevented from maturing seed, and an order that within one 
year such noxious weeds shall be permanently destroyed, and 
prescribing the manner of their destruction and shall forthwith 
give notice to the occupant of the lands where the noxious Aveeds 
exist, and if he shall neglect to obey such order within the time 
so ordered the trustees may cause such noxious weeds to be pre- 
vented from maturing seeds or may cause such noxious weeds to 
be permanently destroyed and the cost of the work shall be re- 
covered from the owner by a special tax to be certified by the 
township clerk in the same manner as other road tax not paid. 

Section 4. Road Funds May Be Expended. The destruction 
of noxious weeds in the public highway and other public places 



17. 

is hereby made a part of the road work of the township trus- 
tees and the county supervisors and they shall have authority to 
expend road funds for the destruction of weeds. 

Section 5. Property Tax. The laAv as it appears in section 
fifteen hundred and twenty-eight (1528) of the supplement to 
the code, 1907, is hereby amended as follows, namely : By in- 
serting- after the comma in the eighth line thereof the following 
words: "and for the destruction of noxious weeds in public 




Russian Thistle, a — mature plant ; b — seedling, about two weeks after 
germination, natural size ; c — flower han?ins: from the axil and remaining 
suspended by minute hairs in the ordinary inverted position of a rolling plant 
enlarged 3 diameters ; d — flower viewed from above and in front, showing 
the calyx lobes forming a cone-shaped body, and the large membranaceous 
spreading wings, enlarged 3 diameters ; e — seed, with flower part removed ; 
enlarged 5 diameters ; f — embryo removed from seed, enlarged 7 diameters. 
(U. S. Dept. of Agr., Bull No. 15.) 

highways and other public places," and by striking out the word 
"four" in the tenth line of said section and inserting the word 
" six " in lieu thereof. 



18. 

Section 6. School of Instruction. Between November and 
the succeeding April of each year the county supervisors shall 
call a meeting of the township trustees and the road supervisors 
of the county to consider the best methods of weed extermina- 
tion and road buildini*-, secure services of exi^erts to give in- 
struction in road building and weed destruction. For such at- 
Icndance the same comixinsation shall be allowCiJ to the 
trustees and road supervisors and the county supervisors as is 
allowed by law for other services, to be paid as other expenses. 
The expenses of experts herein provided for may be paid from 
the county road fund. 

S'^ction 7. Cutting of Weeds on lli;^:hways. It shall be the 
duty of the township trustees and other officers directly respon- 
sible for the care of public highways to cause to be cut near the 




Lamb's Quarter. Goosefoot (Chenopodinm album). A branch with den- 
tate leaves and inflorescence. 1 — flower with calyx. 2 — seed. (U. S. Dept. 

surface all weeds on the public highways in their respective dis- 
tricts at such times and in such manner as to prevent seeds from 



19. 

nifttiiring. 

Section 8. Penalty. Any person, firm or corporation violating 
any of the provisions of this act, or any township trustees, in- 
spector or other officer who neglects or fails to perform the duties 
incumbent on him under the provisions of this act, shall be guilty 
of a misdemeanor and shall be punished by a fine not exceeding 
one hundred dollars ($100.00). 

Section 9. Repeal. The law as it appears in sections fifteen 
hundred and sixty-two (1562), fifteen hundred and sixty-two-a 
(1562-a) and fifteen hundred and sixty-three (1563) of the sup- 
plement to the code, 1907, and sections fifteen hundred and six- 
ty-four (1564) and fifteen hundred and sixty-five (1565) of the 
sode are hereby repealed. 

Approved April 21, A. D., 1909. 

OTHER VV^EDS. 

This list does not include by any means all of the injurious 
weeds, but some of the worst. In some parts^ of the state some 
weeds are more injurious than others. Quack grass is more im- 
portant in northern Iowa than in southern. The horse nettle 
is most troublesome in southern Iowa ; cocklebur is troublesome 
in all parts of the state. Tlie velvet weed, the smooth dock, 
curly dock, and burdock are widely distributed. 

TREATMENT OP WEEDS. 

Weeds in order to be eradicated need various treatment. The 
annual and biennial are not so difficult to exterminate as the per- 
ennial. The first and most important consideration is clean cul- 
tivation. In nearly every case this will destroy the annual weeds. 
The land for corn should be plowed in the fall. The good farmer 
will practice rotation of crops. If he uses the follo^ving rota- 
tion : oats, clover and corn, the clover field can be plowed under 
after the removal of the crop. The land will be reasonably clean, 
because the cloevr is an excellent plant to keep many weeds down, 
especially if the growth is rank. In the spring the field should be 
disced, and the seedlings of many young plants will be destroyed. 
The corn field should then be given clean cultivation. 

It is common practice in Iowa to sow oats directly on the corn 
stubble, simply discing. This is bad practice. It would be far 
better if the corn could be cut and the stalks used for fodder, 
the field ploAved in the fall and the oats sown in a clean field. 
Usually the corn fields are so weedy in Iowa that it is difficult 
to get a clean field of oats. The time is coming when the Iowa 
farmer will cultivate his fields more thoroughly. 

Clover can be sown with oats, if the stand is even the ground 
will be pretty well covered the next season. In Iowa clover is 
usually treated as a biennial. This allows two years for a clover 



20 

crop. The above treatment can only be recommended for an- 
nuals. ]\lany of the seeds of weeds will germinate but some will 
keep their vitality for some years as sweet clover and Indian 
mallow or butter print. The seeds of both weeds are known to 
keep their vitality for more than half a century. 
Perennial Weeds. — The above methods will only partially destroy 
the perennial weeds. Quack grass, Canada thistle, and weeds 
of this character need special treatment. If the leaves of these 
perennial weeds are prevented from growing the weed will be 
killed in the course of time, they will starve usually, however, in 
ordinary methods of cultivation, but some plants are not noticed 
and these give rise to new plants. Let me give a few weeds with 
specific treatment. 




Quack Grass (Agropyron repens). Creeping rootstocks and a number of 
stems (culms), a splkelet at a, each containing a number of flowers, b — a 
spikelet with sterile glumes at 2 and flowers above. 



2L 

TREATMENT FOR A FEW SPECIAL WEEDS. 

Quack Grass. — This is the most difficult weed to exterminate in 
Iowa. There is no easy method. It can be removed by giving 
the field a shallow plowing, in the summer follow with a harrow, 
bringing the roots to the surface and continue discing and har- 
rowing until most of the "roots" are destroyed. Late summer 
and fall is the time to do this. The next season this may be 
followed with a crop of sorglium sown very thickly. This will 
probably remove most of the quack grass, but not all. Hemp 
may be sown in place of sorglium. Dewey claims that several 
fields where quack grass was abundant, the hemp plant has ma- 
terially held the quack grass in check. The pasture method has 
been recommended by Prof. Spillman and what I have seen in 
Iowa would lead me to believe that it is an excellent method. 
The field containing quack grass is put in meadow and pastured 
for two or three years in this way. This method causes the 
roots to come to the surface. They spread less freely in the 
meadow than in cultivated ground. The soil is plowed two to 
three inches deep in the summer, then harrowed two or three 
times to bring the "roots" to the surface; these may then be 
removed from the soil and burned. If the season is favorable, that 
is dry, two or three harrowings will accomplish the killing, but if 
wet some "roots" will keep alive and it may be necessary to plow, 
say not less than six inches. After this has been done two or three 
times the land will be nearly free from quack grass. The field 
should be watched and when quack grass appears, it may be re- 
moved by digging up and hoeing. Deep plowing will also destroy 
the roots, but this can seldom be done well and some "roots" 
are to be seen near the surface which will develop ncAV plants. 
The roots of quack grass are shallow^ rooted. 

The Cover MetJiod. — The cover method can be applied when 
the patch is a small one. For this use tarred paper overlapping 
the edges. Leave the paper on the quack grass for six months. 
A heavy coating of straw, six inches to one foot, will also be 
serviceable, this brings the roots to the surface where they can be 
raked off and burned ; then plow, harrow and cultivate. 

Canada Thistle and Horse Nettle. — These weeds are deep rooted 
and in order to destroy them it will be necessary to plow the 
field, follow with a harrow two or three times and keep the field 
clean for the rest of the season. The work should be done in 
midsummer; if all of the plants cannot be reached by the har- 
row it may be necessary to cut the plant off with a hoe. Sodium 
arsenite and iron sulphate may also be used. It is sometimes ad- 
visable if the patch of thistle occurs in a field to get it in pasture 
and place a lot of salt around the Canada thistle. Stock will 



22^ 

then destroy the weed. 

Morning Glory and Milk Weed. — Morning glory and milk weed 
can best be kept down by thorough and continued cultivation. If 
a field is badly infested with morning glory it is best to get it 
into pasture, allowing hogs and sheep to pasture closely. The 
cultivation method according Cox used in some places is as fol- 
lows : 

"Several methods for accomplishing this eradication have been 
successful. Clean cultivation is one of the best in many cases. 
It is essential to employ such implements as will keep down the 




Wild Morning Glory {Convolvnlus scpium). Two large bracts at the base 
of each tlower. A common troublesome weed in fields, meadows and waste 
places. (U. S. Dept. Agr. ) 

top growth successfully. Where the weed occurs in patches these 
sliould be marked ofT and given special attention. 

"The bindweed may be greatly reduced or entirely destroyed 



23. 

by seeding the land to alfalfa. The frequent cutting and the 
shading effect of this crop are the determining factors. Alfalfa 
should be followed by a cultivated crop to complete the work of 
destruction. 

"Pasturing with hogs has been successful in killing bindweed, 
since hogs are quite fond of the underground parts. This me- 
thod can be used with both ordinary pasture and fallow laud. 
Results can probably be obtained in less time in the latter case." 

Indian Mallow. — This weed is an annual. It is not difficult to 
exterminate, cultivation will destroy it. The great difficulty 
with this weed and the Shoo fly is that the seeds retain their 
vitality for many years. There are cases on record where a per- 
centage of the sei'ds of Indian mallow germinated after the lapse 




Greater Ragweed or King Head (Ambrosia trifida). Sometimes called 
Horseweed. Upper part of a branch, staminate flowers above, pistillate 
flowers just above the leaves, a — a so-callod seed more properly an involucre 
with a bract on the right hand side, b — with bracts removed. U. S. Dept. 
Agr.) 



24^ ^ 

of half a century. No matter how much cultivation you give 
the soil a new crop of weeds will appear. 

Sweet Clover. — This biennial weed is common in many parts of 
the state. It produces a tap root which is not difficult to exter- 
minate by cultivation. As in the preceding ease the seeds retain 
their vitality a long time. 

Greater liagwced or Kinghead. — This weed is a troublesome 
pest in many Iowa fields along fences and railroads. The plants 
are easily destroyed in fields by cultivation. The seed probably 
retains its vitality for some time. Iron sulphate, 100 pounds 
to a barrel of water will destroy it. Plant clean seed. 

Nimhle Will or Drop-Seed Grass. — This station has received 
many letters complainiug about this weed. The character of the 
"roots" is so different from that of the roots of quack grass and 
the other perennial weeds that we have mentioned before that it 
is not difficult to exterminate. The roots of this weed and the 
allied species are more or less clustered. In an experiment con- 
ducted to exterminate this weed we found that by giving a 
shallow plowing of four or five inches and harrowing to expose 
the roots to the sun, they were killed, no growth making its ap- 
pearance during the rest of the season. Of course this is not 
effective during rainy weather. 

Cocklehur. — The cocklebur is a serious menace to cultivated 
crops in many parts of the state, more especially in southern 
Iowa. The best method of combating the cocklebur is the rota- 
tion of crops and clean culture. When a field is in corn, the 
field should be thoroughly cultivated and none of the plants al- 
lowed to mature seed. If they cannot be caught by the cultiva- 
tor, it may pay to kill the remaining plants with a hoe, or to pull 
them by hand. The corn should be followed with winter rye and 
then oats, using the oats as a nurse crop for clover and timothy. 
Leave the field in meadow for at least two years and then if pos- 
sible turn it into pasture. This certainly eradicated the cockle- 
bur, ragweed and many other annual weeds. 

Summer Fallow. — Undoubtedly this is a splendid method for 
the eradication of weeds. I am not using the term, however, as 
it is ordinarily used. To plow and then leave fallow for the 
summer, but constant cultivation and harrowing must be resorted 
to in order to remove the weed. The field must be kept free from 
weeds during the summer and fall. 

The Use of Chemicals. — In recent years many experiments have 
been made with various chemicals to destroy weeds. Among 
them iron sulpliate, sodium arsenite, corrosive suhlimate, copper 
sulphate and common salt. 

Some of these substances like sodium arsenite and corrosive 



25. 

suhlimate are strong poisons. The copper sulpliate is also poison- 
ous but less so than the other solutions. Sodium arsenite will de- 
stroy Canada thistle and many other weeds. It may be used 
at the rate of V/-^ pounds to 52 gallons of water. Stock must 
be kept away when the thistles are treated. The treatment must 
be repeated as often as thistles appear. Corrosive suhlimate was 
found to be efficient in killing many weeds, but is not to be recom- 
mended on account of its very poisonous nature. Salt, when ap- 
plied in sufficient amount is efficacious, but it is expensive when 
used in this way and can only be used as I have indicated for 
Canada thistle and Horse nettle. Iron sulpliate, which is a by- 
product in the manufacture of wire is cheap, costing in 100 pound 
bags, 92 cents per hundred pounds F. 0. B. from several Iowa 
points. If bought in 200 pound bags it costs 5 cents less per 
hundred pounds. It comes in granulated form, is readily soluble 
in water and may be made in various strengths of solution. For 
most plants it is used at the rate of 100 pounds to a barrel of 
water. The solution cannot stand over night. It may be applied 
with a hand or traction sprayer. I have found it efficacious for 
the following plants: Mustard, ragweed or kinghead, smart- 
weed, dandelion, artichoke, velvet weed, small ragweed, lamb's 
quarter, may weed, hedge mustard, pigweed, boot jack, etc. In 
fact the majority of weeds found in grain fields readily yield to 
the application of this spray. 

WEEDS OF SPECIAL CROPS. 

Small Grain. — It is well known that certain weeds occur with 
certain crops since the very earliest times ; such weeds as common 
mustard, darnel, corncockle, vetch and bindweed or wild buck- 
wheat have been found with small grain. These weeds are as 
common in Europe as in the United States. They are found 
wherever small grain is cultivated. Formerly it was difficult to 
remove these weed seeds from the grain, but with modern me- 
thods of screening has made it possible to remove most of the 
weed seeds. 

Corn. — Locality sometimes determines the kind of weeds found 
in the field; in southern Iowa cocklebur, horse nettle, are com- 
mon. In northern Iowa quack grass and artichoke occurs. The 
smartweeds, fox tail pigeon grass, crab grass, shoestring, milk- 
weed, pigweed and morning glory are common in all parts of 
the state. In early spring northern nut grass may appear; 
easily recognized by the yellowish appearance of the field. The 
plant has grass-like leaves and spreads by its "roots." Rag- 
weeds are also common in all parts of the state; velvet weed is 
common and in western Iowa marsh -elder and sunflower are 
abundant. 



26^ 

Garden Weeds. — The most common garden weeds are purslane, 
pigweed, lamb's quarter, crab grass, nimble will, fox tail, spurge, 
boot jack, smartweed, speedwell, horse weed, etc., are quite uni- 
versal in the state. 

Meadoivs. — The more important weeds in clover meadows are 
curled and smooth dock, fox tail, nimble Avill, horse weed, pep- 
per gras.s and smai'iv.eed, yarrow, pigeon grass and small rag- 
weed. The buckhorn, braeted plantain, chicory, carrot, white 
catchfly, evening eatchfly, black medick and yellow clover are 
occasional and of recent introduction. 

Pastures. — In Iowa pastures the hoary vervain with blue flow- 
ers in long spikes. Small ragweed, pigeon grass, fox tail and 
golden rod are the most conspicuous weed in all parts of the 
state. 

Roadsides. — The weeds of the roadside are generally much the 
same as those occuring in adjacent lields. In eastern Iowa dog 
fennel or may weed, yellow clover and jimson weed. The fol- 
lowing are general in the state: Small ragweed, greater rag- 
weed, horse weed, pitch forks, golden rod, morning glory, par- 
snip, milk weed. In western Iowa marshelder, sun flower, stink 
weed, fetid marigold are among the most important weeds. 

Poisonous Weeds. — The laity should become more familiar 
with the poisonuos plants of the state. There are a great many 
plants which are more or less poisonous to man and lower ani- 
mals, a few are, however, deadly poisonous. Some of these dead- 
ly poisonous plants are found in all parts of the state. The 
most poisonous of these is the cowbane which occurs in low 
grounds, has v/hite flowers occurring in umbels, leaves divided, 
fleshy roots, clustered, of a pungent odor and taste. The roots 
are deadly poisonous, a small amount not larger than a hazel 
nut taken in the fall, winter or spring has caused death to a 
boy. In the year 1909 near Boone two boys were poisoned. 
One lad a high school boy picked up some of the roots which 
were turned over by a farmer while breaking a meadoAV. The 
boy was carried to a farm house in the neighborhood and a 
call sent for a doctor. The doctor made a rapid trip to the 
house in his automobile, taking the boy, but when the hospital 
was reached he died. The second boy died under somewhat dif- 
ferent circumstances. This boy later evidently picked up some 
of the plant to show the doctors what his companion had eaten 
and later he developed symptoms resembling those found in 
poison ivy poisoning. Similar cases have been reported else- 
where. Some persons who pull up the plant get eruptions on the 
skin. I am told that the same thing occurs when persons pull 
or come in contact with the leaves of the cultivated parsnip 



27. 

runing wild. This plant has yellow flowers and a straight tap 
root. The root so far as I know is not poisonous at least I am a 
witness to the fact that the root of the wild plant is not poison- 
ous since I have eaten it. Jimson weed is another poisonous 
plant. The plant is narcotic and has a pungent odor. It has 
large white flowers leaves and a spiny "pod" (capsule) with 
numerous blackish seeds. These seeds are very poisonous. Poison 
ivy is another poisonous plant of the state which is not generally 
recognized by the laity. It is often mistaken for Virginia 
creeper, but is readily distinguished by the three leaves — the Vir- 
ginia creeper having five — the leaves of the poison ivy are also 
wider. The poison ivy plant may grow erect or creeping over 
bushes and up trees. The berries are white, while those of the 
Virginia creeper are blue. Poison hemlock is another poison- 




Cowbane {Cicuta maculata). Common in low ground; flowers white, stem 
hollow, fasciled, fleshy roots, "seed" fruit to the right ; cross section lower 
left hand corner. (U. S. Dept. Agr.) 

ous plant in the state, as yet not common it belongs to the 
same family as the cowbane and parsnip. The plant has a ranl^' 
smell something like mice. The flowers are white, small in um- 



28. 

bels. This is the plant that Socrates used to kill himself. Of 
the other poisonous plants I may mention the seed of castor oil ; 
the bark of black locust, the flowering spurge with milky juice, 
the cultivated poppy, mandrake or may apple sneezeweed with 
yellow flowers found in marshes. AVilting sorghum is poisonous 
to stock. The leaves of black cherry and the seeds of plum and 
cherry are poisonous. The so-called mushroom should be avoided 
at all times, especially such as are brilliantly colored. We have 
several deadly poisonous species in Iowa. While there are many 
edible ones, unless you are familiar with them, they had better 
be left alone. 

V^^HAT TO DO IN CASE OF POISONING. 

As soon as possible use an emetic to produce vomiting, use 
tartar emetic; salt and gruel may be given, fallow by infusions 
of hot coffee and epson salts. In case of poison ivy poisoning 
wash with soap immediately and follow with acetate of lead. 



29. 



APPENDIX. 



Descriptions of a Few Weeds Especially of the Iowa Weed Law. 

GRASS FAMILY — ( Gramiiieae.) 
We have a large number of weedy plants in this family. In 
addition to those mentioned above, atiention may be called to 
the sandbnr, sproutiug crab grass, crowfoot grass, Johnson grass, 
chess or cheat, etc. Mention may also be made of the fact that 
wheat, rye, barley, oats and corn belong to the same family. 




Foxtail or Piegon Grass (Setaria glauca) . Annual root, a — sheath and 
part of leaf, b — a splkelet with bristles and glumes and cross st.riated "seed", 
c-d-e-f — other views of the flower, f showing stamens and stigmas exserted ; 
pistil and stamens enclosed by the palea. (Charlotte M. King.) 

YELLOW FOXTAIL — {Setaria glauca (L.) Beauv.) 
An erect annual one to two and one-half feet high, flat leaves 
bristly cylindrical spike, from one to three inches long. The 
heads are slender and the bristles tawny yellow. The small seeds 



30^ 

of this species are conspicuously cross striated and are easily dis- 
tinguished from the next species because of its larger size and by 
it cross striation. This species also comes up in grain fields after 
harvest, hence seeding the soil abundantly. 

GREEX FOXTAIL — {kSctarid viridis (L) Beauv.) 
An erect annual from one to three feet high, leaves four to 
twelve inches long Avith rough margins, greenish, more or less 
compound cylindrical spikes from one to five inches long or even 
in some cases six. Bristles few, much longer than the spikelets. 
Spikelets one-twelfth of an inch long, the chaff (second and third 
glumes) as long as the minute chaff (fourth glume), the latter 
being dotted and striate. A single head produces an enormous 
number of seeds. When fields are sown to oats this plant comes 
up in the fall and late summer ,seeding the soil. 




Quack grass with a head somewhat more enlarged. (U. S. Dept. Agr.) 

QUACK GRASS — {Agropyron repens (L.) Beauv.) 
A perennial with widely spreading but shallow rootstocks which 



31. 



form dense mats. Flowering stems numerous, smooth, floAvers 
in spikes; leaves from 4 to 12 inches long, smooth or sometimes 
pubescent ; spike 3 to 10 inches long ; the separate parts of the 
spikes are spoken of as spikelets, these contain from 4 to 8 flow- 
ers. The chatty scales of the spikelets are spoken of as the empty 
glumes. Each flower has a flowering glume and a palet ; each 
flower contains stamens and pistils. 

This plant, quack grass, is closely related to western wheat 
grass which may be readily distinguished by the giaucus green 




Squirrel Tall Grass, Wild Barley (Hordeum jubatiDii). Winter annual 
or annual, a — part of stem, b — portion of spike showing the sterile and fertile 
flowers and the long awned glumes, c — single flower v/ith long awned glume. 
A troublesome weed everywhere in the state. (Charlotte M. King.) 

Drop Seed Grass or Wild Timothy (Muhlenbergia racemosa) . I single 
spikelet to the right. Stalk with roots (rootstock) clustered. 

color which forms a decided contrast to the ordinary green of 
blue grass or other grasses in this state. The spikelets, too, are 
denser and thicker. This grass is commonly found along rail- 



32^ 

ways. Slender wheat grass (Agropyron tenerum) has slender 
spikes from 4 to 8 inches long; the numerous rootstocks are ab- 
sent. Quack grass is frequently mistaken for drop seed grass 
{Muklcnhergia mexicana) but this may be readily distinguished 
from quack grass by its clustered thick and short rootstocks and 
for this reason sometimes it is called the turkey foot grass. The 
spikes containing the seed are slender. The empty glumes are 
nearly equal. 




(Jrab grasses. Left hand figure common Crab grass (panicum sanguinale) ; right 
hand figure Smooth Crab grass (panicum glabrum). 

SQUiRRELTAiL GRASS — {Hordeum juhatum L.) 
An annual or winter annual from six inches to two feet high 
producing fibrous roots. It forms solid and compact bunches. 
Leaves not unlike those of blue grass, but paler in color, from 
two to four inches in length, margins scabrous. Flowers in a 
dense spike from two to four inches long, pale green or purplish 
in color. The spike consists of a number of one-flowered spike- 



33. 

lets, three occurring at each joint, only one is perfect (bearing 
stamens and pistil). The two other spikelets are awl-shaped 
and rudimentary ; these are borne on short stalks. One of these 
sterile spikelets occurs on each side of the perfect flower which 
bears a long awn. At each joint will be found six empty long- 
awned glumes spreading at maturity. These give to the plant 
the bristly appearance at maturity. When mature the spike 
breaks up into joints consisting of the rudimentary spikelets and 
a perfect flower, so that each joint has one "seed." The num- 
ber of "seeds" in a spike varies from thirty-five to sixty. A 
single cluster of plants may therefore produce from three hun- 
dred to two thousand mature "seeds." The plant has a won- 
derful capacity for "stooling. " From a single plant as many 
as forty spikes may be produced, and the number no doubt often 
exceeds this. 

CRAB GRASS— (Pan icum sanguinale L.) 

A much branched, leafy annual one to three feet high, spread- 
ing on the ground, Avith erect, smooth, spreading culms, frequent- 
ly rooting at the lower joints. Joints smooth, though more fre- 
(juently bearded with defiexed hairs. Sheaths loose, generally 
pilose ; hairy, ciliate on the margins, with a membranaceous ligule. 
Leaves two to four inches long with rough margins, occasionally 
pilose at the base. Flowers produced in digitate spikes hence the 
common name finger grass is sometimes given it. Spikelets less 
than one-eighth of an inch long in pairs, one nearly sessile the 
other with a stalk. Each flower consisting of two sterile glumes 
(chaff) and the flower proper. The first bract very small, the 
second about one-half to two-thirds as long as the spikelets, us- 
ually hairy on the margin. The third glume somewhat longer 
than the fourth which is five nerved and usually silky-villous 
along the marginal nerves. Fourth glume smooth and acute. 
The fruit is minute, pitted and cross striated, light straw color 
except where the sterile glumes remain attached. These are gray 
in color and minutely hairy. 

SEDGE FAMILY — (Cyperaceae.) 

Of the Sedge Family the most important weed in the state is 
the northern nut grass (Gyperus escvlentus) ; this plant is read- 
ily recognized by the yellowish cast of the corn field in the 
spring and the little plant has corms or bulbs, and with roots 
which enables it to spread. 

DOCK AND SMARTWEED FAMILY — (Polygonaceae.) 

This family also contains a large number of important weeds 
many of them are very troublesome to our crops. Mention may 
be made of smartweed, tanweed or devil's shoestring, sheep sor- 
rel or horse sorrel, all common weeds in this state. 



34^ 

CURLED DOCK — {lUiiiicx crispus L.) 
This weed is a smooth perennial from three to four feet high, 
leaves with stronyly wavy and curled margins, lanceolate and 
acute. In the lower leaves the bases somewhat truncate or in- 
clined to be heart shaped. The flowers are collected in dense 




Curled Dork (Ramex crispus) in clover meadows and along roadsides. A 
common European weed. (U. S. Dept. of Agr.) 

whorls, extended or prolonged into racemes, entirely leafless 
above, but below with small leaves. The flower consists of six 
sepals, the outer herbaceous, leaflike, the three inner larger and 
.somewhat curled, and after ^lowering forming the valves of the 
fruit. These surround the three angled fruit (achene) all the 
valves bearing a grain. 



35. 



PEACH-LEAVED DOCK OE PALE DOCK— {Kumex altissimiis Wood). 

A tall perennial with multiple roots; leaves oval, oblong, lan- 
ceolate extending into a point, pale and thickish ; the 'flowers in 
spike-like racemes or panicles, flowers with nodding pedicels, the 
valves of the flower are obscurely heart-shaped; commonly with 
a conspicuous inflated grain. Common in alluvial soil every- 
where in the state. 

SHEEP SORREL — {Kumex acetosella L.) 

A lo^v smooth annual or perennial, usually the latter, growing^ 
from six to twelve inches high; producing an erect stem ,with 
horizontal, creeping, woody rootstock or rhizome; petioled, nar- 




Sheep sorrel (rfmex acetosella) . 1 staminate flower; b. pistillate flower. (U. S. 
Dept. Agr.) 

rowly hastate, narrow, lanceolate leaves, the upper linear ; flow- 
ers on jointed pedicels ; dioecious small in a terminal naked pan- 
icle ; small green calyx j exserted stamens; the valves (inner calyx 



36^ 

lobe) not enlarging in fruit. 

GOOSEFOOT FAMILY — {Chenopodiaceae.) 
This family contains a number of common and troublesome 
weeds, among them the common lamb's quarter or goosefoot 
{Chcnopodium album), a weed commonly found in gardens and 
along roadsides. Spinage also belongs to this family. 
PIGWEED FAMILY — {Amavantliaccae.) 
This family contains a number of troublesome weeds, iu this 
gtate one of the most common being the common pigweed {Amar- 
anthus retroflexus) , and the common Iowa tumble weed {A. 
graccizans.) 

PINK FAMILY — ( Caryoplnjllaceac.) 
Of the weeds of this family mention may be made of the cow 
herb, common in grain fields, the evening catchfly, wakerobin, 




Corn Cockle (Agrostemma Githago) . A hairy plant with purple flowery 
The long outer segments are lobes of the calyx, 2 — capsule with calyx and 
seeds, 3 — kidney-shaped seed. (U. S. Dcpt. Agr.) 



_37. 

etc. The carnation belongs to the same family. 

CORN cocKijEr—{ Agrostemma GitJiago L.) 
A hairy annual weed, clothed with long, soft hairs. Leaves 
linear-lancoolate, acute or long acuminate; flowers purple and 
long peduneled ; calyx lobes long, linear, surpassing the purple 
red petals ; seeds large, roughened and black. 

PURSLANE FAMILY — {Poitiilacaceae.) 
This family contains but one common weed, the common pusley 
or purslane {Portulaca alcracea) which is common in gardens 




Purslane {Portulaca oleracea). General view of plant to the right. 1 — 
flower in cross section, pistil in center with ovules attached, stigmas above, 
stamens to the right and left, 2 — ^A capsule with a line in the middle where 
tlie capsule splits. 3 — The same witli top of capsule removed showing the 
seeds. 4 — Seed. 5-6 — Stamens. (U. S. Dept. Agr.) 

everywhere in the state, and the common moss rose of Peru is 
cultivated. 



38, 




anf ';^lSf pla'ce^.^'T^'^ iXtAgrr"'^' ^ ^°"^'-"" ^'^'^ ^- gralnflelda 



39. 

CROWFOOT FAMILY — {Ranunculaceae.) 
A number of weeds are members of this family, among them 
the common crowfoot with a sharp acrid taste {Ranunculus 
ahortivus) ; also such cultivated ornamental plants as the peony, 
larkspur, aconite, columbine and clematis. Many of these plants 
are poisonous. 

MUSTARD FAMILY — ( Crucifcrac.) 
Among- the common weeds not described below mention mav 




Butter Print or Indian Mallow (^Ahutilon theophrasti) . A velvety pubes- 
cent annual, flowers and capsule , e ach division with several seeds. (U. S. 
Dept. Agr.) 

be made of the tumbling mustard, pepper grass {Lepidium 
apctalum), common everywhere in the state. Cabbage, turnip 
and rutabaga, and mustard belong to the same family. 
MUSTARD OF ENGLISH CHARLOCK — {Brassica arveusis (L.) Ktze.) 
Lower leaves nearly divided to the middle, with the divisions 
unequal, the terminal lobe larger. Upper leaves sessile much 



^ 

smaller than the lower. Flowers yellow, large and very fragrant. 
Pods one to two inches long, irregular in outline, appearing 
somewhat nodose, three to seven seeded or more occasionally. 
The upper part of pod forms the beak. Seeds round, brownish 
black, darker than in B. nigra and minutely pitted. The pods 
of black mustard shorter and angled. Seeds of all of the mus- 
tards mucilaginous. There are many other mustards in the state 
like hedge mustard, pepper grass, etc. 




Wild Carrot {Daucus Carota). Common in the East in clover meadows 
and introduced into this state with clover seed. A bristly hairy biennial. 1 
— general view, 2 — flower with stamens, pistil, corolla, 3 — fruit. (U. S. Dept. 
Agr.) 

MALLOW FAMILY — {Molvuceae.) 
A number of verj' common weeds in this state belong to this 
family, among them the common cheeses, and crisp mallow, also 
such ornamental plants as the hollyhock. 



41. 

BUTTER PRINT OR VELVET WEED — {Ahutilon TJieophrasti Medic.) 
A tall annual from two or four feet high ; leaves roundish 
heart-shaped and velvety, pubescent, taper pointed, pedicels 
shorter than the leafstalk ; flowers small with yellow corolla ; pod 
consisting of 12 to 15 beaked carpels which are pubescent. Com- 
mon in waste places and vacant lots. Seeds preserve their vital- 
ity for a long time. 




Field Dodder {Cuscuta arvensts) . Found on clover. a — flower; b — 
flower spread apart ; c — capsule with stamens and styles therein ; d — seed. 
(Dewey Division of Botany, U. S. Dept. Agr.) 

Alfalfa Dodder (Cuscuta epithymum). a — flower; b — flower spread apart 
to show stamens and corolla ; c — capsule showing styles ; d — seed. (U. S. 
Dept. Agr.) 

PARSELY FAMILY — {UnihelUferae.) 

This family contains a number of weeds some of them most 

troublesome. In addition to those described below mention 

may be made of the poison hemlock {Conium maculatum), some 

of the cultivated plants are the carrot, parsley, lovage and dill. 



42. 

This family contains some of the most poisonous plants in the 
vegetable kingdom, like the cowbane or water hemlock and poison 
hemlock. 

PARSNIP — (Pastinaca saliva L.) 
A biennial with grooved stems; pinnately compound leaves, 
with ovate to oblong cut toothed leaflets. Fruit oval to flattened 
with broad wings. This tall stout glabrous or somewhat pubes- 
cent biennial is as escape fi'om cultivation. It has a straight tap 
root in place ol' multiple thick fleshy roots as the poisonous hem- 
lock or cowbane frequently called parsnip in this state. 





Horse Nettle {Solanum caroUnense), a perennial weed troublesome in 
southern Iowa. Potato-like flowers and prickly stem. (Division of Bot.. 
U. Dept. Agr.) 

Buckhorn {Plantago lanceolata). "With a timothy-like head and elong.ited 
leaves. Common in clover meadows. (Charlotte M. King.) 

CAUHKOT — (Daiiciifi Carota L.) 
A biennial or annual with bristly stems and pinnately deeom- 



*^ 

pound leaves; bracts surrounding the flowers leaf-like; white 
flowers in umbels becoming concave. This plant with a straight 
tap root has been widely distributed with clover and alfalfa. It 
is one of the most pernicious weeds of the eastern meadows. 




Bull thistle (Cirsium lanceolatum) . A troublesome biennial weed common 
in woods, pastures and along roadsides. (U. S. Dept. Agr. ) 

cowBANE. WATER HEMLOCK — {Cicuta maculata L.) 

It is a smooth marsh perennial two to five feet high with pin- 
nately compound leaves two or three times pinnate; the leaves 
have long petioles, the coarsely serrate leaflets are lanceolate to 
oblong lanceolate one-fifth inch long. Stalks of the umbellets 
numerous and unequal. Flowers white, fruit broadly ovate to 
oval, small one and one-half inches long. Grows in marshes 
and in low grounds. The stems spring from thick fleshy under- 
ground roots that taper at the lower end. These usually number 
from three to five, but single specimens are also met with. On 



iL 

cutting the roots a sharp pungent odor is given off. 
MORNING GLORY FAMILY — {Convolvulaceae.) 
In addition to the weeds described below, we have the Euro 
I'ean bindweed or morning glory, the southern morning glory 
{Ipomoea purpurea) and related species. The sweet potato be- 
longs to this family. 




Canada thistle (Cirsium nrvcnse). A common troublesome weed in gar- 
dens, roadsides and sometimes in clover fields. Notice tlie perennial roots at 
2^ and the flowers at 3. (U. S. Dept Agr.) 

DODDER — {CuSCUta Spp.) 

The dodders are leafless excepting the small scales on the 
stems, herbs of reddish or yellowish color, with thread-like stems 
twining around the plants upon which they live. They pierce 
the plant witli small nnd sliort I'ootlets which are called suckers 
or haustoria. The seeds are small, yet there is stored sufficient 
nourishment in them to give the embryo a start. The seed ger- 



.45 

minates in the soil and grows sufficient in length to allow it to 
come in contact with the plant upon which it lives, when it im- 
mediately sends in its suckers, and thus becomes established upon 
the plant as though it were a part of the host. 

The dodders contain no chlorophyll, the green coloring matter 
tound in leaves, and hence cannot make food, that is, make starch 
out of raw material such as ordinary green leaves do, but must 
derive nourishment entirely from the host upon which they live. 
Such plants are called parasitic. 




Cockle Bur (Xanthiuin canadenst.) Weed of cornfields and roadsides. 
(U. S. Dept. Agr.) 

We have two troublesome dodders in this state, the clover dod- 
der {Cuscuta epithymum Murr.) on alfalfa and clover, with 
slender stem with elongated stigmas and field dodder (C. arven- 
sis) with capitate stigmas. 

HEDGE BINDWEED OR MOfiNtlsTG GLORY — {ConVOlwXuS Sepiwm L.) 



47^ 

NIGHTSHADE FAMILY — {Solanact'ae.) 
This family contains a number of very troublesome and per- 
nicious weeds, among tbem the common black nightshade (*S'oZa- 
num nigrum) with small white flowers, the Buffalo bur {S. ros- 
tratum) with prickly stems and fruit and yellow flowers, leav,es 
resembling those of the water melon; the ground cherry {Phy- 
salis), the Jimson weed, two types, both species poisonous. Of 
the cultivated plants it contains the potato, tomato and tobacco. 




Burdock (Arctium Lappa). A common biennial weed of waste places, 
gardens and pastures. (Division of Bot., U. S. Dept. Agr. ) 

HORSE NETTLE — {Solamun corolinense L.) 
•Horse nettle is a deep-rooting perennial, propagating freely 
by its underground roots, these running roots are often three 
feet long; stem from one to two feet high, somewhat straggling, 
half shrubby at the base; stem hairy or merely roughish with 
minute hairs which are star-shaped, alscv armed with stout subu- 



46. 

Smooth, occasionally, however, pubescent, twining around sup- 
ports or trailing. Leaves triangular, halberd or arroAv-shaped, 
the tip acute, or pointed, the basal lobes obliquely truncate or 
sinuate lobed. The flowering peduncles four angled with two 
leaf-like bracts which are commonly acute. Corolla is white or 
tinged with rose purple. 




Small Ragweed (Ambrosia artemisiaetolia). With deeply divided leaves 
and branches with flowers. J — head with staminate flowers, 2 — pistillate 
flower containing the "seed." (U. S. Dept. Agr.) 

MINT FAMILY — {Lohiatae.) 
A number of troublesome weeds like the catnip, common ger- 
mander or wood sage, and peppermint, with creeping "roots"; of 
the cultivated species the scarlet sage, peppermint, hyssop, etc. 
Many of the plants have a pungent flavor, and square stem, and 
thus are easily recognized. 



48^ 

late yellowish prickles which are usually numerous ; leaves obloiig 
or sometimes ovate, obtusely sinuate, toothed or lobed or deeply 
cut, two or four inches long. The flowers are borne in what are 
called racemes, which later become one-sided; the outer part of 
the flowers, the calyx, consist of slender lobes, the corolla is light 
blue or white, an inch or less in diameter. The flowers are fol- 
lowed by the yellow globose berries, half to three quarters of an 
inch in diameter. The seeds are yellowish, a little less than one- 
twelfth of an inch long, minutely roughened. The flowers re- 
semble those of the common potato, and arc blue or white, an 
inch or less in diameter. The yellow berries also resemble those 
of the potato. The spiny character of the leaves and the further 
resemblance of the flower to the potato should render it easy of 
detection. 

PLANTAIN FAMILY — (Plautaciinaceae.) 

Of the plantains the most common weed not described is the 
common dooryard plantain of which there are two kinds, Plan- 
tago major and P. Pugelii; the bracted plantain is becoming a 
troublesome weed in the southern part of the state, especially in 
clover fields. This plant is something like the common plantain 
but the leaves are narower and the heads with large bracts. 
BUCKHORN — {Plmitago lanceolata L.) 

A perennial or biennial, pubescent, with short erect root-stocks ; 
leaves narrowly oblong lanceolata , somewhat shorter than the 
scape, three to five ribbed ; scapes slender with spikes dense, at 
first capitate, later becoming cylindrical ; bracts and sepals scari- 
ious, brownish; calyx of four persistent sepals and glabrous co- 
rolla. Two small smooth brownish seeds found in each vessel. 
COMPOSITE FAMILY — (Compositae.) 

The Composite or Sunflower Family is a large family of plants 
containing some of the most troublesome of our weeds. The fam- 
ily gets its name from the common sunflower which is weedy in 
the western part of the .state, but in addition there are a large 
number of other weeds of this family like the dandelion, May 
weed, sneeze weed, marsh elder, troublesome in western Iowa, 
the leaf looks something like the sunflower, but the flowers are 
like the common ragweed, tansy, and so on. Of the cultivated 
plants attention may be called to the lettuce and chicory. Sneeze 
weed with yellow flowers growing in low ground is poisonous. 
Aster, golden rod, horse weed and dandelion belong to this fam- 
ily. 

BULL THISTLE — {Cirsium lanceolafum. Willd.) 

A branching biennial, three to four feet high, tomentose, be- 
coming dark green and villous or hirsute with age, branchlets 
bearing large heads ; leaves lanceolate, decurrent on the stem with 



49. 

prickly wings deeply pinnatifid, the lobes with rigid prickly 
points, upper face roughened with short hairs, lower face with 
a cottony tementum ; heads one and three quarters to two inches 
high, bracts of the involucre lanceolate, rigid when young, more 
flexible with age, long attenuated prickly pointed spreading tips, 
arachnoid woolly ; flower hermaphrodite, tube of the corolla ten 
lies long, anther tips acute, filaments pubescent, achenes smooth, 
one and a half inches long, pappus of numerous plumose bristles. 
CANADA THISTLE — {Civsium arvsnse (L.) Scop.) 

A smooth perennial, spreading by creeping roots and root- 
stocks, one to three feet high, corymbosely branched at the top ; 
stem smooth ; leaves lanceolate, sessile, and deeply pinnatifid, 
lobes and margins of leaf with spiny teeth ; heads small, three- 
fourths to an inch high, bracts appressed, the outer Avith a broad 
base, inner narrow, all with an acute, never spiny tip ; flowers 
purple, dioecious, one plant with stamens and the other with 
pistils. Common in many parts of the state. 

COCKLE BUR — {Xanthium canadense Mill.) 

A course, rough annual from one to three feet high, stem 
marked with brown punctate spots; leaves alternate, cordate or 
ovate, three nerved, long petioled. Flowers monoecious, stamin- 
nate and pistillate flowers in different heads, the pistillate clus- 
tered below. The involucre of the staminate flowers somewhat 
flattish of separate scales, receptacles cylindrical. Scales of the 
fertile involucre closed in fruit two beaked, containing two 
achenes (seeds). The bur is densely prickly and hispid, the 
achenes are oblong without pappus. At the upper end of the 
involucre are two large prickles. 

Each bur, as stated above, contains two flowers which develop 
into the "seeds." The statement is frequently made "that one 
of these may germinate the first year, and the other lie dormant 
until a later time. It has been found that if a bur lies in such 
a position that one seed is up and other down, the one next the 
soil may germinate while the other remains dormant. This is 
one reason why the plant is difficult to exterminate. 

GIANT RAGWEED. KiNGHEAD — (Amhrosia trifida L.) 

This weed is a stout scabrous, hispid or nearly glabrous an- 
nual, three to twelve feet high. Leaves all opposite and petioled 
three nerved, deeply three to five lobed, the lobes are ovate and 
lanceolate and serrate, the upper leaf sometimes ovate and undiv- 
ided; flowers monoecious, staminate borne in spikes surrounded 
by the larger bract-like leaves. The involucre is turbinate to 
obovoid, five to seven ribbed, beaked, each rib bearing a tubercle 
near the summit; the involucre enclosing a single oily seed. 



50 

SMALL RAGWEED — (Ambrosia art emisiae folia L.) 
This weed is a puberulent or hirsute annual, branched, one to 
three feet high; leaves thin, once to twice piunatifid; the upper 
leaves are alternate, the lower, usually opposite, pale or canescent 
beneath. Flowers monoecious, the staminate above and the pis- 
tillate in the lower axils of the leaves. The fertile heads are 
obovoid or globose. Short beaked. Four to six spined. 
BURDOCK- — {Arctium Lappa L.) 
A coarse, branched biennial from a foot to three feet high; 
hairy; leaves large, roundish or heart-shaped, thin, obtuse, entire 
or dentate, floccose tomentose beneath. Petioles deeply fur- 
rowed, heads of purplish or whitish flowers, clustered or some- 
what corymbose. The involucre surrounding the flowers (heads) 
are lengthened into hooked tips, glabrous or slightly cottony. 

Where burdocks are allowed to grow freely the fruit clings 
to the fleece of animals, often forming large balls Avhich may be 
found on the tails of cattle and horses. When they are common 
where sheep pasture the burdocks work into the wool which 
soon becomes of little value. The plant is enormously produc- 
tive. 



51. 



Suggestions for the Teacher 



The most important point in connection with the study of 
plants is to train the powers of observation. The child should 
learn to discriminate between plants. While important to know 
the name of a plant, it is far better to be able to tell what the 
differences are. For instance, we have about 1100 different kinds 
of flowering plants in the state of Iowa. They differ from each 
other by one or more characters. The student should learn the 
most important differences. To illustrate, we have in Iowa, two 
kinds of morning glory, one the common bindweed or wild 
morning glory, native to Iowa, with flowers from one to two 
inches long, leaves large halberd, or arrow shaped, and running 
rootstocks often called "roots" but these so-called roots have 
small scales. The European bindweed has much smaller flowers, 
less than one inch long, leaves small ovate and arrow shaped, 
and running roots, no scales on these. 

Many people do not know that we have two kinds of dandelion 
in the state. The common one {Taxaxacum officinale,) olive green 
seeds and coarsely divided leaves, and the red-seeded one {Tar- 
axacum crythrospermuin) with red or dark brown seed and 
deeply divided leaves. 

There are eight thistles in the state, all of these are easily 
distniguished by a very simple key which I will insert here for 
convenience. The characters are all very obvious. 

A. Perennial. Plants living year after year. 

1. Heads large, numerous. 

a. Leaves woolly both sides — Woolly Thistle (C can- 

escens, N. AV. la.) 
a. Leaves hairy on lower surface — Field Thistle (C. 

discolor, la. general. 

2. Heads small. Leaves slightly woolly underneath — 

Canada Thistle (C. arvense, la. general.) 

3. Heads large, usually 1, blooms early — Prairie Thistle— 

(C. Hillii, la. general.) 

B. Biennial. Plants form flowers the second season and then 
die. 

1. Heads with numerous sharp spines. Leaves very spiny 



52^ 

— Bull Thistle (C lanceolatum, la. general.) 
2. Head not spiny but sticky. 

a. Leaves not hairy or sparingly ; in swamps — Marsh 

Thistle (C. muticum, N. la. rare.) 
a. Leaves hairy at least below. 

Heads very large ; in swamps — Iowa Thistle — (C, 

ioicdise, meadows, la. general.) 
Heads smaller ; in woods — Wood Thistle (C. altis- 
simum, E. la.) 
The C. of the Sunflower family (Compositae), stands for the 
genus Cirsium, which includes all of the true thistles. There are 
other so-called thistles but the botanical name should only be 
applied to the plants of this genus. The Russian thistle is not 
a true thistle but belongs to the Goosefoot Family {Chenopo- 
diaceae.) The student should early recognize that certain plants 
belong to some particular family and with a little practice such 
plants as the sunflower, aster, goldenrod, purple cone flower, 
may weed, and dandelion, will readily be recognized as belonging 
to the composite family. 

To facilitate the work of the teacher I have added a few ques- 
tions which the student should answer. If the teacher is not 
familiar with the terms that are here used, any of the larger 
dictionaries will assist in getting the definitions, sepals, petals, 
stamens, pistils, bracts, ray flowers, achene, etc. Simple leaves 
may be linear, hastate, halberd, cordate, acute, acuminate, cleft, 
lobed, dissected, and sagittate. Compound leaves may be pin- 
nate (rose), and i:)almately (horse chestnut) compound. Fruits 
may be berry (black nightshade, horse nettle), capsule (Jimson 
weed), pod (clover and sweet clover), achene (sunflower, thistle), 
caryopsis or grain fruit (corn, wheat, crab grass). Flowers, 
regular (morning glory, strawberry), irregular (sweet clover, 
sweet pea), polypetalous (crowfoot, clover), gameopetalous 
(morning glory, horse nettle), apetalous (smartweed), calyx col- 
ored like petals (smartweed.) 

QUESTIONS AND TOPICS. 

1. Describe accurately in your own language the chief points 
of the following weeds: Greater or giant ragweed, dandelion, 
quack grass, burdock, velvet weed, dock, parsnip, coeklebur and 
other weeds mentioned in the Iowa weed law. 

2. Note the methods of reproduction in the following weeds : 
Canada thistle, dock, quack grass, foxtail, burdock, bull thistle, 
coeklebur, horse nettle, velvet weed. 

3. Note the difi'erence in the underground parts of the fol- 
lowing weeds : Morning glory, quack grass, milkweed, sheep 



, . 53. 

sorrel. Determine whether roots or underground stems. Are 
there any small scales present on the underground portions ? 

4. How do you know that quack grass is a stem? How do 
you know that milkweed is a root? 

5. Determine the duration of life of as many weeds as pos- 
sible. For example, foxtail (annual), wild barley or squirrel 
tail grass (winter annual), bull thistle, wild carrot and burdock 
(biennial), quack grass, Canada thistle, tan weed, morning glory 
(perennial.) 

6. Determine the root and stem character of as many weeds 
as possible. Determine also the space they occupy in the soil, 
whether deep or shallow rooted and how these roots injure the 
crops. 

7. Determine the number of seeds produced by some indi- 
vidual weeds and make a record of the result. 

8. Now determine the weed seeds produced per acre of some 
weed. 

9. Make a study of the following weed seeds : Foxtail, cockle- 
bur, burdock, plantain, catnip, ragweed, dock, smartweed, butter 
print or velvet leaf, may weed or dog fennel, mustard, sweet 
clover, dodder, lambs quarter, buckhorn, wild carrot and pig- 
weed. 

10. Why are weeds detrimental to agriculture? 

11. Determine the number of different kinds of weeds on a 
given area. If you cannot name them dry the specimens and 
send to me for identification. 

12. In what ways do weeds spread? Give a concise account 
of the methods and give illustrations of each. 

13. What weeds are scattered by the wind, water, snow, ani- 
mals and explosive properties. 

14. Germinate some of the weed seeds. Determine the per- 
centage of germination and study the characters of the weed 
seedlings. How many seeds in the eocklebur and how many seeds 
germinate the first season. 

15. Try to germinate the seeds of some weeds immediately; 
take another lot of the same kind, stratify in sand or earth and 
allow them to freeze. Plant the seed in April. If you find any 
difference determine the percentage in each case. 

16. Determine the percentage of impurities in clover seed. 
Obtain bulletin 115 of the Iowa Agricultural Experiment Sta- 
tion which gives methods in detail. This bulletin will be sent 
upon application. 

17. Make a collection of weeds and weed seeds. Specimens 
can be preserved and dried for reference. 



54;; 

18. Determine the kinds of weeds found in the following 
places : The corn fields, garden, roadsides, pasture and in vacant 
lots, door yards and barn yards. 

19. After these points have been carefully studied and the 
habits of the plants determined, suggest a method of extermina- 
tion of weeds studied. 

20. Determine the yield of corn or other crops per acre in 
some clean fields and compare them with some weedy fields. 
Which fields give the largest yield. 

21. Become familiar with a few poisonous plants such as 
poison ivy, which is frequently a climbing plant, jimson weed, 
a rank smelling herb with large white flowers, the cowbane with 
clustered roots and clustered white flowers in umbels like parsnip. 

BIBLIOGRAPHY. 

The following papers and books may be used for reference: 

Pammel, L. II. Some weeds of Iowa. Bull. la. State College 
Experiment Station, Ames, 70. Russian thistle. Bull. 26 ; Quack 
and Wheat grasses. Bull. 83 ; Press bulletins, 11, 12 and 13. 
These may be had, except No. 70, by writing Prof. Curtiss, Ames. 

Pammel, L. H. and Charlotte M. King. Notes on Eradication 
of Weeds with experiments made in 1907 and 1908. Bull. 105. 
Iowa Agricultural Experiment Station. 

Results of Seed Investigations for 1908 and 1909. Bull. 115. 
See also Bull. 88 of the same station by L. H. Pammel, R. E. 
Buchanan and Charlotte M. King. Iowa Agricultural Experi- 
ment Station. 

Pammel, L. H. Weeds of the Farm and Garden. Orange Judd 
Co., New York. About 300 pages. In press. 

Floras and Manuals. The following cover our territory. 

Britton. Manual of the Flora of the Northern States and 
Canada. Henry Holt & Co. 

Robinson and Fernald. Cray's ^lanual of Botany of Northern 
United States. American Book Co. 

Clark, Geo. H. & Fletcher, J. Farm Weeds of Canada. Pub- 
lished by the Department of Agriculture, Canada. Price $1.00. 

Htiehcock, A. S. & Geo. L. Clothier. Report on Kansas Weeds. 
Bulls. Kansas Agricultural Experiment Station, 57 ; 80. 



Key for Families 



Plants grass-like. 

Stems solid, 3 angled, Cyperaceae 34 

Stems hollow, round in cross section, Gramineae 30 

Plants not grass-like. 

Flowers inconspicuous. 

Flowers with thin, not greenish bracts, Amai-anthaceae 37 
Flowers greenish, succulent hetbs. Chcnopodiaccae 37 

Flowers greenish, 3 sepals enclosing the seed, acrid herbs, 

Polygonaceae 34 
Flowers conspicuous. 

Succulent plants, Portulaceae 40 

Plants not succulent, acrid, sepals petal-like, 

Polygonaceae 34 
Plants not succulent, acrid, sepals and petals present, 

Ranunculaceae 40 
Plants not acrid. 

Stems with swollen joints, . . Caryophyllaceae 37 

Stems with joints not swollen. 

Flowers regular of separate parts. 

Flowers in umbels, UmbelUferae 42 

Flowers not in umbels. 

Pungent herbs, 6 separate stamens, 

Cmciferae 40 
Bland herbs, stamens in one set, 

Malvaceae 41 
Flowers in one pie ce, Gamopetalous 
Flowers irregular, stem 4 angled, Labiatae 47 
Flowers regular, stem not 4 angled. 

Twining plants, Convolvulaceae 45 

Not twining plants. 

Conspicuous flowers not in heads. 

Fruit a berry, Solanaceae 48 

Flowers in heads, Compositae 49 

Flowers inconspicuous. 

Plantgainaceae 49 



OCT ^2 mo 



One copy del. to Cat. Div. 



LIBRARY OF CONGRESS 



002 815 000 3 



